The present invention relates to a heat exchanger for an air conditioner, for example, a heat exchanger for a car air conditioner.
With reference to FIGS. 6 and 7, the description will be made of a conventional heat exchanger for a car air conditioner. FIG. 6 shows the visual appearance state of the heat exchanger, and FIG. 7 shows a cross-section taken on line VII--VII in FIG. 6.
As shown in FIG. 6, in a heat exchanger 1, two upper and lower side plates 4 and 4 are provided between a pair of tube-shaped header pipes 2 and 3 (left-side header 2 and right-side header 3) made of aluminum, and both ends of the side plates are inserted into the left-side header pipe 2 and the right-side header pipe 3 respectively and brazed.
A plurality of tubes 5 are arranged between the side plates 4 and 4, and the both ends of the tubes 5 are braze joined with the left-side header pipe 2 and the right-side header pipe 3 respectively. Refrigerant flows through the inside of the tubes 5. Corrugated fins 6 are brazed between each tube 5, and the fins 6 are formed by a thin plate made of aluminum.
In the upper part of the right-side header pipe 3, there is provided an inlet pipe 7 for refrigerant gas, through which the interior of the right-side header pipe 3 is filled with refrigerant gas. The interior of the right-side header pipe 3 is partitioned into two parts, upper and lower, by a partition plate 8, and an outlet pipe 9 for discharging refrigerant liquid is provided in the lower part of the right-side header pipe 3. The inlet pipe 7 is connected to a compressor (not shown) and the outlet pipe 9 is connected to an evaporator (not shown).
The refrigerant gas compressed by a compressor (not shown) is supplied into the upper part (above the partition plate 8) of the right-side header pipe 3 through the inlet pipe 7, and flows inside the plurality of tubes 5. While the refrigerant gas is flowing inside the tube 5, air flows between the fins 6 by a fan (not shown) to cool the fins 6.
The refrigerant gas inside the tubes 5 is heat-exchanged (cooled) by the fins 6 to be liquefied, and flows into the left-side header pipe 2. The refrigerant inside the left-side header pipe 2 flows on the right side in FIG. 6 inside the plurality of tubes 5 below to be cooled by the fins 6 again, and is completely liquefied to flow below (below the partition plate 8) the right-side header pipe 3. The refrigerant liquid which has flowed below the right-side header pipe 3 is discharged to the evaporator (not shown) through the outlet pipe 9.
On assembling the heat exchanger 1, the both ends of the side plate 4 are adapted to be brazed after they are installed to the left-side header pipe 2 and the right-side header pipe 3 in a predetermined state respectively. On installing the side plate 4, one end portion of the side plate 4 is inserted into a slit hole 10 in the left-side header 2 as shown in FIG. 7 for being brazed. The other end portion of the side plate 4 is also installed to the right-side header pipe 3 in the same manner.
In a conventional heat exchanger 1, both ends of the side plate 4 are adapted to be installed to the left-side header pipe 2 and the right-side header pipe 3 in a predetermined state by inserting the end portion of the side plate 4 into the slit hole 10 in the left-side header pipe 2 (right-side header pipe 3).
Since, however, the width of the slit hole 10 is set to be larger than the width of the end portion of the side plate 4, there arises a clearance between the slit hole 10 and the end portion of the side plate 4. The occurrence of the clearance causes errors to angles of installing the side plate 4 to the left-side header pipe 2 and the right-side header pipe 3, and particularly to the positions of the inlet pipe 7 and the outlet pipe 9 of the right-side header pipe 3. This causes obstruction to the piping of the heat exchanger 1, and if the errors are great, there has been a possibility that the heat exchanger 1 could not be assembled.
Also, since the depth in inserting the end portion of the side plate 4 is not regulated, if the side plate 4 is inserted deep in one header pipe, for example, the left-side header pipe 2 side, the depth of insertion on the right-side header pipe 3 side will become exceedingly small, possibly leading to incomplete fixation even if brazed.